Although varenicline (Champix), a smoking-cessation treatment, was recommended for listing by the Common Drug Review (CDR) in 2007, only one CDR-participating drug insurance plan listed it in March 2011 (Saskatchewan). This study estimated the economic impact of delays in the public listing of varenicline in Canada. Using statistical data and peer-reviewed research, social costs and benefits of reimbursing varenicline were estimated. Flows of attempted and successful quitters were projected over a five-year period for three scenarios: immediate listing (2007), one- to four-year listing delays, and no reimbursement. Benefits of public reimbursement of varenicline would have been greatest in the first year ($271 million) and then decreased due to the erosion in smoking prevalence. The current three-year listing delay prevented a projected 17,729 current smokers from quitting, translating into a projected additional lifetime social burden of $700 million. The sizeable opportunity cost of delaying varenicline reimbursement implies broader economic issues for policy makers.